Motions of Earth, Sun & The Moon

Question 1

What is Planetary Movement?

Answer 1

Planets orbit the sun in elliptical orbits which are caused by gravitational forces.

Orbital Period - the period of time that it takes for one “lap” around the sun

Question 2

How many types of motion do planets have?

Answer 2

Two: Rotation and Revolution

Question 3

What is rotation of planets?

Answer 3

Rotation is the spinning of an object around its axis, which is an imaginary straight line running from the North Pole to the South Pole.

The Earth’s rotation around its axis takes 24 hours. The rotation causes day and night.

Question 4

What is a revolution of planets?

Answer 4

• Revolution – the movement of one object travelling around another.
• It takes the Earth one year (365 days) to revolve around the Sun. This allows us to see different stars in different seasons.

Question 5

What is the Earth’s tilt?

Answer 5

• The Earth’s axis is tilted at about 23.5 degrees.
• The angle of the Earth’s axis in combination with its revolution causes our seasons.

Question 6

How seasons change based on where you are?

Answer 6

Depending on your location on earth, you will experience different seasons at different times of the year.

In January:
Winter in Northern Hemisphere
Summer in Southern Hemisphere

In July:
Summer in Northern Hemisphere
Winter in Southern Hemisphere

Question 7

Why is it summer in the Northern Hemisphere when it is tilted towards the Sun and winter when it is tilted away?

Answer 7

• During the summer, the Northern Hemisphere is tilted towards the Sun,
• During the winter the Northern Hemisphere is tilted away from the Sun.

Question 8

What are Solstices and Equinoxes?

Answer 8

Solstices
* longest and shortest days of the year

Equinoxes
* occur when the day and night are equally as long

Question 9

What are different moon phases?

Answer 9

• New Moon – The Moon is between Earth and the Sun, and the side facing Earth is dark.
• Waxing Crescent – A small crescent of the Moon is visible as it starts to grow.
• First Quarter – Half of the Moon is visible, with the right side lit up.
• Waxing Gibbous – More than half of the Moon is lit, but it’s not full yet.
• Full Moon – The entire Moon is fully lit by the Sun.
• Waning Gibbous – The Moon starts to shrink, but more than half is still lit.
• Last Quarter – Half of the Moon is visible again, but the left side is lit.
• Waning Crescent – A small crescent remains as the Moon moves back to the New Moon phase.

Question 10

How long is the moon revolution period?

Answer 10

28 days

Question 11

What are the Tides?

Answer 11

• High and low tides are caused by the moon.
• The moon’s gravitational pull generates a tidal force.

Question 12

What are Eclipses?

Answer 12

• An eclipse happens when a planet or a moon gets in the way of the Sun’s light.
• Here on Earth, we can experience two kinds of eclipses: solar eclipses and lunar eclipses.

Question 13

What are Solar Eclipses?

Answer 13

• Occurs when the Moon gets in the way of the Sun’s light and casts its shadow on Earth.
• This only occurs during the day.
• Total Eclipse: happens about every year and a half somewhere on Earth
• Partial Eclipse: when the Moon doesn’t completely cover the Sun, happens at least twice a year somewhere on Earth

Question 14

What are Lunar Eclipses?

Answer 14

• Occurs when the Earth gets in the way of the Sun’s light hitting the Moon.
• The Moon can look reddish because Earth’s atmosphere absorbs the other colors while it bends some sunlight toward the Moon.
• During a total lunar eclipse, the Moon is shining from all the sunrises and sunsets occurring on Earth.

Question 15

What are some facts about the moon?

Answer 15

• The Moon always faces the same direction towards Earth
• The moon is not a perfect sphere, it is more like a lemon
• No one knew what the “dark side” of the moon looked like until we built spacecraft to take a look